1) Field of the Invention
The present invention relates to a novel piperazinylethylaminocarbonyl-containing butadiene-acrylonitrile copolymer and to a process for producing the same.
2) Description of Related Arts
Conventionally, as adhesives for adhesive tapes for fixing a leadframe, which is used in the interior of a resin-sealed type semiconductor device, synthetic rubber type resins such as polyacrylonitrile, polyacrylate or acrylonitrile-butadiene copolymer are used solely, or with being modified or mixed with another resin.
The adhesive tapes, etc., for fixing a leadframe are required not only to possess good reliability at a level required for semiconductor and processability at the time of taping, but also to have sufficient adhesive strength immediately after taping and heat resistance sufficient for withstanding the heating at the stage of assembling a resin-sealed type semiconductor device. However, the adhesives which have conventionally been used are insufficient in heat resistance, etc., and it has been, therefore, desired to develop an adhesive which is allowed to adhesion and curing at a comparatively low temperature and has sufficient heat resistance and to develop a novel material for producing the same.